ASTM_E_1382_-_97_2015.pdf

Designation:E138297(Reapproved 2015)Standard Test Methods forDetermining Average Grain Size Using Semiautomatic andAutomatic Image Analysis1This standard is issued under the fixed designation E1382;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThese test methods may be used to determine the mean grain size,or the distribution of grainintercept lengths or areas,in metallic and nonmetallic polycrystalline materials.The test methods maybe applied to specimens with equiaxed or elongated grain structures with either uniform or duplexgrain size distributions.Either semiautomatic or automatic image analysis devices may be utilized toperform the measurements.1.Scope1.1 These test methods are used to determine grain sizefrom measurements of grain intercept lengths,intercept counts,intersection counts,grain boundary length,and grain areas.1.2 These measurements are made with a semiautomaticdigitizing tablet or by automatic image analysis using an imageof the grain structure produced by a microscope.1.3 These test methods are applicable to any type of grainstructure or grain size distribution as long as the grainboundaries can be clearly delineated by etching and subsequentimage processing,if necessary.1.4 These test methods are applicable to measurement ofother grain-like microstructures,such as cell structures.1.5 This standard deals only with the recommended testmethods and nothing in it should be construed as defining orestablishing limits of acceptability or fitness for purpose of thematerials tested.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 The sections appear in the following order:SectionSectionScope1Referenced Documents2Terminology3Definitions3.1Definitions of Terms Specific to This Standard3.2Symbols3.3Summary of Test Method4Significance and Use5Interferences6Apparatus7Sampling8Test Specimens9Specimen Preparation10Calibration11Procedure:Semiautomatic Digitizing Tablet12Intercept Lengths12.3Intercept and Intersection Counts12.4Grain Counts12.5Grain Areas12.6ALA Grain Size12.6.1Two-Phase Grain Structures12.7Procedure:Automatic Image Analysis13Grain Boundary Length13.5Intersection Counts13.6Mean Chord(Intercept)Length/Field13.7.2Individual Chord(Intercept)Lengths13.7.4Grain Counts13.8Mean Grain Area/Field13.9Individual Grain Areas13.9.4ALA Grain Size13.9.8Two-Phase Grain Structures13.10Calculation of Results14Test Report15Precision and Bias16Grain Size of Non-Equiaxed Grain StructureSpecimensAnnexA1Examples of Proper and Improper Grain BoundaryDelineationAnnexA21These test methods are under the jurisdiction of ASTM Committee E04 onMetallography and are the direct responsibility of Subcommittee E04.14 onQuantitative Metallography.Current edition approved Oct.1,2015.Published February 2016.Originallyapproved in 1991.Last previous edition approved in 2010 as E1382 97(2010).DOI:10.1520/E1382-97R15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.Referenced Documents2.1 ASTM Standards:2E3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE112 Test Methods for Determining Average Grain SizeE407 Practice for Microetching Metals and AlloysE562 Test Method for Determining Volume Fraction bySystematic Manual Point CountE883 Guide for ReflectedLight PhotomicrographyE930 Test Methods for Estimating the Largest Grain Ob-served in a Metallographic Section(ALA Grain Size)E1181 Test Methods for Characterizing Duplex Grain SizesE1245 Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals by Automatic ImageAnalysis3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,(feature-specific measurement,field measurement,flicker method,grain size,gray level,and threshold setting),see Terminology E7.3.2 Definitions of Terms Specific to This Standard:3.2.1 chord(intercept)lengththe distance between twoopposed,adjacent grain boundary intersection points on astraight test line segment that crosses the grain at any locationdue to random placement of the test line.3.2.2 grain intercept countdetermination of the number oftimes a test line cuts through individual grains on the plane ofpolish(tangent hits are considered as one half an interception).3.2.3 grain boundary intersection countdetermination ofthe number of times a test line cuts across,or is tangent to,grain boundaries(triple point intersections are considered as112intersections).3.2.4 image processinga generic term covering a varietyof